Brilliant blue is a shade of blue, or may refer to:
Color RAL 5007 brilliant blue, an RAL color
Chemicals Brilliant blue FCF, a dye Brilliant cresyl blue, a stain used in microscopy Coomassie brilliant blue, a dye Remazol Brilliant Blue R, a dye
Entertainment "Brilliant Blue", a side B song on the single "Kyū Jō Show!!" by the Kanjani Eight Brilliant Blue (manga), a manga Daphne in the Brilliant Blue, a manga and television series
Butterflies Junonia rhadama, a butterfly of islands in the Indian Ocean Lepidochrysops asteris, a butterfly of South Africa